System as well as a method for controlling a self moving robot

Abstract

A system provided with a base station ( 2 ) comprising a signal emitting module, a self movable robot comprising at least an energy storage, a sensor for sensing this signal emitted by signal emitting module of the base station and a processor for controlling the movement of the robot by means of the sensed signal to return the robot to the base station. The robot comprises means for controlling the movement of the robot to move the robot randomly over a surface, whereby the absolute position of the robot is not memorized, means for marking the interrupt location ( 5 ) where the movement of the robot is interrupted to return to the base station and means for returning the robot from the base station to the interrupt location ( 5 ) by means of said marking.

The invention claimed is: 
     
       1. A system comprising:
 a base station comprising a first signal-emitting module for emitting a first signal, and 
 a self-movable robot comprising at least an energy storage, a sensor for sensing the first signal and a processor for controlling movement of the robot, based on the sensed first signal, to return the robot to the base station,
 said robot: 
 moving randomly over a surface, without memorizing absolute positions of the robot, 
 providing a marking at an interrupt location where the random movement of the robot is interrupted, and 
 returning from the base station to the interrupt location by using said marking. 
 
 
     
     
       2. A system according to  claim 1  where the marking at the interrupt location comprises at least one beacon which is placed by the robot on at least the interrupt location and remains on the interrupt location at least until the robot is returned from the base station to the interrupt location. 
     
     
       3. A system according to  claim 2  where the at least one beacon comprises a second signal-emitting module for emitting a second signal that can be sensed by the sensor of the robot. 
     
     
       4. A system according to  claim 2  where several beacons are placed on a path traversed from the interrupt location to the base station for use in returning the robot to the interrupt location. 
     
     
       5. A system according to  claim 1  comprising a memory for memorizing movements of the robot from the interrupt location to the base station, said means for returning the robot from the base station to the interrupt location using said memorized movements. 
     
     
       6. A method for controlling a self-moving robot, the method comprising:
 moving the robot randomly over a surface without memorizing absolute positions of the robot, 
 interrupting the random movement of the robot for return to a base station, 
 providing a marking at an interrupt location where the random movement of the robot is interrupted, 
 sensing a signal emitted by an emitting module of the base station, 
 moving the robot by means of the signal to the base station, 
 returning the robot from the base station to the marked interrupt location by using the marking, 
 resuming the random movement of the robot over the surface. 
 
     
     
       7. A method as in  claim 6  where the marking provided at the interrupt location comprises a beacon. 
     
     
       8. A method as in  claim 7  where the beacon emits a signal for guiding the robot to the interrupt location. 
     
     
       9. A method as in  claim 6  further including memorizing movements of the robot from the interrupt location to the base station for use in returning the robot to the interrupt location. 
     
     
       10. A method for controlling a self-movable robot for cleaning a surface, said method comprising:
 moving the robot randomly over the surface without memorizing absolute positions through which said robot moves; 
 upon the occurrence of a predetermined condition of the robot, interrupting the random movement of said robot for return to a base station; 
 providing a marking at a location where the random movement of the robot is interrupted; 
 sensing a signal emitted from the base station and utilizing said signal for guiding the robot to the base station; and 
 returning the robot from the base station to the marking, where the random movement of the robot was interrupted. 
 
     
     
       11. A method as in  claim 10  where the robot comprises a rechargeable energy storage and the predetermined condition comprises a charging level that is lower than a predetermined reference level. 
     
     
       12. A method as in  claim 10  where the predetermined condition comprises the need to empty a dust container. 
     
     
       13. A method as in  claim 10  where the predetermined condition comprises the need to refill a liquid container. 
     
     
       14. A method as in  claim 10  where the marking provided at the location where the random movement of the robot is interrupted comprises a beacon. 
     
     
       15. A method as in  claim 14  where the beacon emits a signal for guiding the robot to the location where the random movement of the robot is interrupted. 
     
     
       16. A method as in  claim 10  further including memorizing movements of the robot from said location to the base station for use in returning the robot to said location.